1981 Kitamura M-2 Fanuc 6M-B YZ Simultaneous Movement

[TFGC]

Hello-

I was warming the spindle up on my 1981 Mycenter 2 Fanuc 6M-B in MDI in the 2nd Command screen using only S and M commands. When I went to home the Z axis both the Z and Y axis moved together. Not sure what happend. Has anyone had this experience before?

Both axiis move independent of each other when programmed in Edit mode, but in Manual Pulse, Jog, Rapid and Homing they move together.

Any ideas are welcomed!

[Al_The_Man]

When you use the home routine, do you have to hold the respective button on all the time untill homed?
The reason I ask is that in the edit mode, it is purely a software command, but in the rest, it involves hardware input which might suggest the Z & Y are being selected simutaneously, possibly by wiring malfunction/short etc.
You never mentioned the control going in to alarm, so it appears the control thinks this is legitimate operation.
Alot depends on just how the machine tool builder implemented the hardware/input,(if he did not interlock anything).
Failing this, it could be a firmware fault on the servo IC's on the MB, but due to working OK in RUN does not seem to point to this.
Most of the harware fault suggestions can be detected by use of the Diagnostic I/O table.
Al.

[TFGC]

Al-
When homing each axis via the homing selector position YES I do have to hold the + button down until each is zeroed out.

Correct also that I am not receiving any alarms.

Should I start by removing the Pendant panel and see if there are any crossed wires or am I to look somewhere else?

Each axis was working perfectly fine and independently before yesterday's occurrence.

Thanks Al.

Matt

[Al_The_Man]

If you have an axis selector switch etc, I would look on the diagnostic screen for the I/O and see if the respective switch inputs register on/off and if any are not simultaneously on.
Al.

[Allyd]

If I remember correctly the selector switches in the pendant are connected to a circuit board and from there a multi core cable runs back to the cnc control. We used to have a problem with the solder mask on this circuit board coming off and corrosion shorting the tracks together. A quick rub over with a brass brush (power off) and a coat of varnish did the trick. If the selectors are connected with a ribbon cable look for signs of arcing where the ribbon enters the connector. The system is only meant to home one axis at a time. PS if an axis is already at home but requires rehoming if you select the -ve jog button the axis will jog off and back automatically.

[TFGC]

Thank you both Al and Allyd-
So far I have:
1. Checked the selector switch on the pendant...it looks good but I will clean the contacts to be sure.
2. Looked through my DGNOS screens and found the following "flickering" numbers:
195, 196, 197, 238, 239, 704, 713, 714, 800, 801, 802 & 804.
I do not have the correct Fanuc 6M-B Maintenance Manual for my machine and still wouldn't know what to do with these numbers if I did!
NOTE: By "flickering" I mean multiple numbers in every string are flipping between 1 and 0.

In my PC Parameters #195 is the only parameter to be blinking this way, but in my diagnostics pages the numbers listed above are all flickering.

Any suggestions are welcomed!

[Al_The_Man]

I don't have a 6m manual here, I have one at the shop tomorrow, but on the i/o diagnostic page, probabally the first screen, you should see the push buttons register when you push them, push and hold them and the bit should change from 0 to 1 and stay as ling as the button is pushed. make sure that the XYZ select button goes on to off as you rotate it. This way you can identify each function, This is why it helps to have the i/o listing for the address of each function.
I wil also look them up tommorow.
Al.

[Al_The_Man]

I happened to be at a customer today with a Kitamura M4 with a Fanuc 6M so it is probabally a similar machine, unfortunately he could not find his electrical prints but I checked the Diagnostic screen and it appears the jog and home buttons are common to all axis so it pretty much only leaves the Axis Select switch.
The inputs on his machine were:
X 40.4
y 27.4
Z 29.5
A 23.3
They are all over the map, I expected them to be together.
Anyway, only one of these four should on at any given time. If two or more are on, that is your problem.
Those byte address are 0 to 7 from right to left. e.g. 40.4 is word 40, 4= fifth bit from right.
Al.

[TFGC]

Thank you Al so much for your time. I will report back after I have gone through the process.

[Al_The_Man]

I will report back after I have gone through the process.

What happened to the report?
Al.

[TFGC]

Sorry al-

I had my electrician spray the contacts on the XYZ selector switch and it seemed to do the job.

Now though, my ATC carousel spins non-stop when the manual ATC rotate button is pressed once. Do you think this switch needs to be cleaned as well?

[Al_The_Man]

Sounds like it is sticking on?
Al.